Reserve apparatus for oil stills



Dec. 8, 1931. e. E. LOFGREN RESERVE APPARATUS FOR OIL STILLS Filed May 6, 1929 %VEN {OR 2? 1 6% E a. BY

00 o oo o oo o 00 Patented Dec. 8, 1931 .UNITED STATES PATENT OFFICE eus'rarnium torenun, or mouurvsmvon, new roux, Assrcuon TO Burns STEAM STORAGE-INC or new YORK, N. Y., aoonroaarron or DELAWARE 1 RESERVE Arr' nA'rus son on. s'rILLs Application filed. May 6, 1929; Serial No. 360,626.

My invention'relates toplants for the tillationof oil and the like.-

In supplying oil I to stills, electrically driven centrifugal pumps have been found 5 to give advantages over steam pumps. How: ever, electrically driven pumps have a d 1sadvantage in that the supply of electricity may stop and if the pumps stop the stills are likely to burn out or explode. l To avoid he disadvantage and permit the use of electrically driven pumps, I adda steam pump "as a reserve unit Operated by steam from a steam accumulator as will presently appear. i I '16 The nature of the invention will be apparent' from the following description taken in conjunction with the accompanying drawing showing, diagrammatically, a distillation plant in accordance with the invention.

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- On the drawing, reference character. 10

designates an oil'still for vaporizing oil fired by coal or other fuel. Oil to be distilled or cracked is supplied to the still through conduit 11 bymcans of centrifugal pump 12 driven by an electric motor 13 receiving electrical current from any suitablesource of supply as an outside main. Oil is supplied to pump 12 through conduit 14 from a tank. Flow through conduit'14 may be started, shut off, or'regulated by means of a hand valve '15. Automatic means may also be supplied to control the flowof oil to the still. 7

Connected to conduit 11 is a pip'e 16. Pipe 16 is connected to the outlet of areciprocating oil pumpl'l'. A conduit 18-connects the inlet of pump 17 with conduit 14. A hand valve 19 in conduit .18 serves to start, stop, or regulateflow of oil through conduit-l8;. Check valves 20 and 21in the supply conduits to pumps 12 and-17 respectively prevent back flow. p I H 1 'Pump 17 is driven by a steam motor 22. Parts 17 and'22 together constitute a steam driven pump. Steam for the steam driven pump is supplied to motor 22 through conduit 23from an accumulator 24. Accumue lator'2t-is a large vessel under pressure and containing water forfabout 90% of its volume. It is made ot relatively heavy steel plating and is well insulated. Steam is supplied tothe accumulator by means of conduit 25 which receives steam from a steam generator 26 comprising one or more steam boilers, orother source of steam.

In conduit 25 is a valve 27 This valve is controlled by a number of steam impulses. It is responsive to pressure in the steam generator, high pressure in the accumulator and low pressurein the accumulator. This valve tends to maintain a constant pressure in the source of steam supply by opening on rise of steam pressure in the source of steam supply and closing on drop, of pressure so as to maintain the impulse pressure constant. Should the accumulator pressure rise to a given value, the valve closes regardless of pressure in the source of steam supply. Should the pressure in the accumulator drop to a given value the Valve will open and act as a reducing valve regardless of the pressure in the source of steam. Valves of this nature are known per se. Toillustrate'the valve function, I have shown two pistons 28 and 29 arranged to move the valve, though it is to be understood that this is merely illustrative. In practice, I use one piston actuated by a plurality of relays. Steam pressure ahead of valve 27 acts through tube 30.

This is the steam pressure of-the source of steam. Increase of steam pressure opens the valve more orless and decrease of steam pressure causes the valve to close. This maintains a constant pressure in conduit 25 ahead of valve 27 in the direction of flow. High pressure of steam in the accumulator, say 220 pounds per squarev inch, acts through tube 31 and closes the valve regardless of pressure transmitted through conduit 30. The valve mechanism can be constructed in known manner to accomplishthis function. If the accumulator pressure drops to a low value, say110 pounds per'square inch, this pressure acting through tube 32 opens valve 27 regardlessof pressure. V

Check valve 37 prevents back flow from the accumulator towardthe steam generator.

A by-pass33 is provided connecting the inlet with the outlet of pump 17 in order to permit pump .17- to run idle or unloaded withoutpumping oil to the still. A valve 3a serves to control the by-pass. Pump 17 and the accumulator are a reserve unit. Pump 12 normally supplies the oil to the still. Should the supply of electricity to motor 13 become shut off or the pump be so affected as to substantially diminish the supply of oil to the still, the still might be burned out or explode before the fires could be put out. lVith the present arrangement, should pump 12 stop or become incapacitated to any extent, pump 17 can immediately be put into service by closing valve 34 in by-pass 33. Of course, if valve 19 is closed, that valve also should be opened.

The accumulator is kept charged at all times and should have suflicient capacity to run pump 17 for twenty minutes or half an hour or such time as may be necessary to permit the drawing of the fires and dissipation of the heating effect in the still sufiicient to relieve the danger of burning out or rupturing of the still.

In plants where no steam is used, a boiler may be used at intervals, say once a week, to charge the accumulator. If a steam reserve pump were to be used without an accumulator boilers would have to be kept in readiness continuously and, even so, a small boiler plant could not be brought up to load in suflicient time to avert danger in case of failure of pump 12.

As illustrated, valve 3& may be controlled either by hand or automatically. I have illustrated one form of automatic control in the form of a centrifugal governor 36 responsive to the speed of pump 12. Should the speed of motor 12 decrease appreciably, governor 36 automatically closes valve 34, thus causing pump 17 to supply oil to the still. Instead of a centrifugal governor for closing valve 34, a volt responsive governor responsive to voltage of the electric supply to motor 13 may be used or a fiow meter responsive to rate of flow in conduit 11 may be used. Instead of closing valve 34, such an automatic governor may open valve 19. It will be obvious that with the arrangement shown on the drawing, valve 19 should be maintained open to permit the reserve unit to be automatically brought into operation. 7

Having thus described my invention, what I claim is:

1. A distillation plant comprising an oil still, a normally operable electrically driven pump connected to the still to supply oil thereto, a steam driven reserve pump connected to the still to supply oil thereto. an accumulator, a steam generator, means to conduct steam from the steam generator to the accumulator, means to conduct steam from the accumulator to the steam driven pump and means to permit unloaded operation of the steam driven pump.

2. A distillation plant comprising a pipe still for oil, a normally operable electrically driven pump connected to the still to supply oil thereto, a steam driven reserve pump connected to the still to supply oil thereto, an accumulator, a steam generator, means to conduct steam from the steam generator to the accumulator and means to conduct steam from the accumulator to the steam driven pump.

3. A distillation plant comprising a pipe still for oil, a normally operable electrically driven pump and a steam driven reserve pump connected in parallel to supply oil to the still from a common source, check valves in the inlet lines to the pumps permitting flow towards the respective pumps, an accumulator, a steam generator, means to conduct steam from the steam generator to the accumulator, means to conduct steam from the accumulator to the steam driven pump and means to permit unloaded operation of the steam driven pump.

4:. An oil distillation plant comprising a pipe still, a normally operable electrically driven pump connected to the still to supply oil thereto, a steam driven reserve pump connected to the still to supply oil thereto, a steam generator, an accumulator, means to conduct steam from the steam generator to the accumulator, means to conduct steam from the accumulator to the steam driven pump, means to permit unloaded operation of'the steam driven pump and means to automatically place the steam driven pump in operation when the electrically driven pump fails.

5. An oil distillation plant comprising a pipe'still, a normally operable electrically driven pump connected to the still to supply oil thereto, a steam driven reserve pump connected to the still to supply oil thereto, a steam generator, an accumulator, means to conduct steam from the steam generator to the accumulator, means to conduct steam from the accumulator to the steam driven pump and means to automatically place the steam driven pump in operation when the electrically driven pump fails.

6. That improvement in the distillation of oil which consists in pumping oil to a still by means of a pump, normally driving said pump by an electric motor, maintaining a steam driven reserve pump in unloaded condition, maintaining a charged storage source of steam for the reserve pump, maintaining a connection for flow of steam from the storage source to the reserve pump and loading the reserve pump to supply oil to the still when the first mentioned pump fails.

7. That improvement in the distillation of oil which consists in pumping oil to a still by a pump, normally driving said pump by an electric motor, maintaining a steam driven reserve pump in unloaded running condition, maintaining a charged storage source of steam for the reserve pump, maintaining a connection for flow of steam from the storage source to the reserve pump and automatically loading the reserve pump to supply oil to the still When the speed of the first mentioned pump falls to an abnormally low value.

In testimony whereof I have afiixed my signature.

GUSTAF EINAR YLOFGREN. 

